Blaze King Sirocco - Burning Combustor too hot?

[nicpottier]

Hi everyone,

Long term lurker, first time poster. I used the information on this forum and the myriad great discussions to settle on what wood stove to replace an old vermont casting knockoff with. That stove could put out some heat but we could never get long burns in the winter, so would just cook us out.

Settled on a Blaze King Sirocco 30 after reading lots of threads and checking them out at dealers. Installed with about 15 feet of double wall stove pipe going to 9 feet of chimney so drafts very well. I've fired it up a few times despite the temperatures really not requiring it (though it was 45 this morning) and so far it is living up to the promises of long burn time and controllable heat. So far, very very impressed. Also loving that glass door, though keeping it clean is going to be a pastime I can see.

My one question is on the catalytic combustor temp. When first firing up the stove and especially after closing the damper when things are really starting to go, I will often peg the catalytic thermometer while running it on high for the first 15 minutes. Even now after turning it down to 2 about 10 minutes ago, it is all the way up.

Is this a concern? Haven't seen any discussions about this in the past. If it isn't meant to run so hot, what strategies are there to bringing that temp down or preventing it from getting as hot? I'm not running full packed loads like I will in the winter, so I don't think it is even running as hot as it will then.

Thanks everyone,

-Nic

 

[jeff_t]

Welcome.

New cats are very vigorous when it comes to burning smoke. It will settle down with some use.

If you are concerned, open the bypass for a bit and let some smoke and heat up the chimney.

 

[Highbeam]

Don't worry about it, relax. The stove is designed to not overtemp the catalyst. The only reason you need to use that cat meter is to determine when it is hot enough to engage the cat and also to be sure you don't set the stat too low and stall the cat. How high it goes or how brightly the cat glows is irrelevant.

 

[Poindexter]

Agree with above. If I recall correctly the cat on my new last year Ashford 30 settled down quite a bit after the first dozen or so burns.

If your wood is drier than about 11-12% that could be a problem, but one year old spruce at (but not under) 12% won't peg the needle at wide open throttle after the first few burns.

 

[webby3650]

Agreed, relax it will calm down after a few weeks of burning.
Also, the glass should stay reasonably clean once outside temps fall enough to really burn the stove. Assuming you have good seasoned wood? That is key to keeping the glass looking good.

 

[BKVP]

One additional tech observation, you can and often will see higher cat temps in the lower burn rates. As you slow down the gases, you increase residence time in the cat, which results in sub par weighted emissions and increased activity, resulting in higher temps. In the AF30.1's, the low burn is actually .49 gr/hr and temps can get up to 1600 F, so as we said in the 70's...chill

 

[Highbeam]

One additional tech observation, you can and often will see higher cat temps in the lower burn rates. As you slow down the gases, you increase residence time in the cat, which results in sub par weighted emissions and increased activity, resulting in higher temps. In the AF30.1's, the low burn is actually .49 gr/hr and temps can get up to 1600 F, so as we said in the 70's...chill

So the "sub par weighted emissions" during low burn is confusing. Are you saying that emissions are extra low (lower than par) during low burn or extra high (higher than par) during low burn? I'm not a golfer but I assumed the goal is a low score so sub-par means a high number. This is confusing because the efficiency and emissions at low burn rates are supposed to be at their best.

 

[Highbeam]

And don't open the bypass to "cool" the cat. The bypass frame is not designed to handle the intense heat of a fire that is too hot. You can warp the bypass frame and then it won't seal in the future. The cat won't get too hot and even if it melted it is easier to replace a bad cat than a bypass frame.

 

[BKVP]

So the "sub par weighted emissions" during low burn is confusing. Are you saying that emissions are extra low (lower than par) during low burn or extra high (higher than par) during low burn? I'm not a golfer but I assumed the goal is a low score so sub-par means a high number. This is confusing because the efficiency and emissions at low burn rates are supposed to be at their best.

Golfers are always different. A birdie? An eagle? Missed biology 101 eh? As you read, .49 is lower than .89 w/a.

 

[jeff_t]

And don't open the bypass to "cool" the cat. The bypass frame is not designed to handle the intense heat of a fire that is too hot. You can warp the bypass frame and then it won't seal in the future. The cat won't get too hot and even if it melted it is easier to replace a bad cat than a bypass frame.

You don't need a rippin' fire to have the cat really hot. Just as likely to have little to no active flame at all.

I surely wouldn't open it with the thermostat on 3 and a box full of hell.

 

[nicpottier]

Thanks for the heads up guys, it does make sense that the cat would be even hotter on low burns since there is more smoke. Is that true with the plain 30's as well? Though I just bought mine it is a 30, not a 30.1, manufactured in April 2014. Fine either way, just curious as I thought the changes for the 30.1 were primarily superficial.

Anyways, thanks for the advice, I've come to relax about the cat temp. Still learning my way around the new stove but such a huge upgrade over the previous and loving that we aren't spewing billows of smoke anymore.

-Nic

 

[BKVP]

Thanks for the heads up guys, it does make sense that the cat would be even hotter on low burns since there is more smoke. Is that true with the plain 30's as well? Though I just bought mine it is a 30, not a 30.1, manufactured in April 2014. Fine either way, just curious as I thought the changes for the 30.1 were primarily superficial.

Anyways, thanks for the advice, I've come to relax about the cat temp. Still learning my way around the new stove but such a huge upgrade over the previous and loving that we aren't spewing billows of smoke anymore.

-Nic

Same deal....